The invention relates to a housing for a crystal accommodated in its interior with polished optical end faces especially for nonlinear frequency conversion in laser applications.
Usually such known housings are provided with windows that are pressed against the jacket housing on the inside by means of a surrounding seal, for example an O-ring, with the housing lids being screwed into the ends of the jacket housing by means of screws so that the windows, clamped firmly by the housing lids, press the O-rings against the jacket housing on the inside. In addition, the crystal is placed in a module in the shape of a circular cylinder or in its cylindrical chamber that extends concentrically with respect to the axis of the cylinder, and is glued there for example. The module is secured in the jacket housing by means of a lateral screw.
The disadvantage of this known housing is the fact that the O-ring is mechanically pretensioned by means of the screw which is both costly and also requires assembly time. Moreover, a larger structural size is required since the screws must always be located outside the useful window surface next to the jacket openings, so that the space required for the thread and the head of the screw must basically be added to the usable diameter.
When the screws for the O-ring are tightened, there is also the risk that if slippage occurs, the outside of the optical window will be damaged. Finally, tightening the module to the jacket housing with the screws can cause leaks, which is undesirable.
The known housings are costly to make mechanically and to install, and many individual parts are required so that there is a danger of dust penetrating the interior of the housing. When the screws are tightened to secure the module, there is also the danger that the optical end faces of the crystal themselves will be damaged. Moreover, this assembly activity is especially risky since because of the sensitivity of the crystal to water, it must generally be handed with gloves in order to prevent moisture on the hands from coming in contact with the crystal.
In general, a housing according to the art is costly to manufacture and costly to install.